It is known to provide a structural partition inside the fuselage of an airplane in order to separate the inside volume into two gas- or liquid-tight zones. For example, one of the zones defined by the partition may be pressurized, unlike the other zone, or one of the zones may be used as a fuel tank. The junction between the partition and the wall of the fuselage is made at an angle that is locally perpendicular to the wall and to the parts of the primary structure of the airplane, which structure comprises frames, stiffeners, stringers, beams, etc.
Such a partition may be installed permanently when the airplane is fabricated. However it may be desirable to install such a partition as a retrofit, i.e. in an airplane that was not originally designed to receive it. This applies in particular for an airplane that has already flown.
Unfortunately, putting such a partition into place raises various problems. Since it is a structural partition, it must be capable of withstanding required levels of force. For this purpose, it is known to fasten the partition to the primary structure by means of fishplates extending on either side of the partition and requiring at least two parts and a plurality of structural fastenings. It is preferable to fasten the partition to the fuselage without cutting into the parts of the primary structure of the airplane so as to avoid endangering its mechanical properties. However, when it is also desired to save weight, such an arrangement is found to be too heavy or to be critical in terms of fatigue. Thus, in certain circumstances, sealing is provided by putting putty into place that is sandwiched between the parts. That solution requires a large number of small pieces of thin sheet metal to be added, which pieces are complex to install.